There is a demand for a thinned, downsized, and lightened IC card or mobile phone. In order that such a demand is met, a semiconductor chip to be built in the IC card or the mobile phone needs to be a thinned semiconductor chip. However, a semiconductor wafer constituting a modern semiconductor chip has a thickness (a film thickness) falling in a range from 125 μm to 150 μm. In this view, it has been said that a semiconductor wafer for constituting a next generation chip needs to have a thickness falling in a rage from 25 μm to 50 μm.
One example of a method for manufacturing a semiconductor wafer having such a film thickness may include a thinning method described below. At first, the thinning method includes combining a semiconductor wafer and a plate material, such as a support plate or the like, to each other via a tape that includes an adhesive layer in each side or via an adhesive agent. The support plate to be used in the thinning plate serves to strengthen the semiconductor wafer after it has been thinned. Subsequently, the thinning method includes grinding the semiconductor wafer by a grinder or the like in a state that the semiconductor wafer and the support plate have been combined to each other, so that a thinned semiconductor wafer is manufactured. Finally, the thinning method includes removing the support plate from the thinned semiconductor wafer.